Machine guns
“Fighting vehicles” weren’t the only military technology that da Vinci thought up. He also conceptualized a “machine gun” cannon. This was the inventor’s solution to the issue of cannons taking too long to load.
In response to that problem, da Vinci sketched a 33-barreled organ, which three rows of 11 guns each. In theory, one row would fire as another would cool and the third would load, so that soldiers using the device could fire upon their enemies with no interruption.
In fact, archaeologists found what they believed to be a triple-barrel cannon inspired by da Vinci’s invention. Per the Telegraph, the bronze cannon (dating back to approximately the late 15th century) closely resembled da Vinci’s primitive “machine gun” design.
“We think it was either made in Venice and brought here, or it may have been made locally,” museum director Marin Curkovic told the Telegraph. “We cannot say with 100% certainty that it was built to Leonardo da Vinci’s designs but the resemblance to his sketches is remarkable. We think there is a very high probability that it was manufactured to his designs.”